UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASH I NGTO N , D.C

. 20460

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

MEMORA N DUM
DATE:
SUBJECT:

TO:

FROM: November 25 , 2013 Response to Public Comments on the Preliminary Environmental Fate and Ecologi cal Risk Assessment for the Registration Review of Fluazinam ( PC Code No. 129098; DP Barcode 0416328 )
Steven Snyderman, Risk Manager Rev ie wer Avivah Jakob , Team Leader Patricia Parro tt , Chief Risk Management and Implementation Branch III Pesticide Re

- evaluation Division (7508W)

### &iP:"~-**.· ~**  Jo se 

### L. Melendez, Chemist ("**jf~** /U?d- Justin Housenger, Biologist

### ~**~** - . Environmental Risk Branch V 

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# 13 Environmental Fate and Effects Division (7507C)
THROUGH: Mah T

. Shamim, Ph.D., Chief Enviro nmental Risk Branch V Environmenta l Fate and Effects Division (7507C)

In response t o the 

### "Preliminary Environmental Fate and Ecological Risk Assessment for the Registration Review of Fluazinam" (Document ID EPA

- HQ-OPP

- 2009-0039-0019 in www.regulations.gov ) (DP Barcode: 0411177 , dated June 4, 20 13), ISK Biosciences Corporation (ISKBC) provided comments during the public comment period. ISKBC is the sole U.S. registrant of record for tluazinam. The purpose of this memorandum is to address those comments. The Environmental Fate and Effects Division (EFED) used an outline-type of format to address the comme nts. The comments were often written verbatim whi le other times they were summarized, as required. EFED 's purpose of the document is to respond to technical/sci e :nce-related questions and comments.



### 11. ISKBC Comment: EFED used the default 35 day foliar dissipation half-life in determining exposure and risk estimates in the T

- REX model rather than values from submitted studies that were used by EFED in previous reviews. ISKB C has submitted two foliar dissipation studies , one on peanut ts (MRID 46991302) and another on potatoes (MRID 46991303). The input value that was pre viously used by EFED for terrestri a l exposure in risk assessment was 7.33 days which repres { :nts the 90th percentile of the upper confidence bound on the mean of six half-lif e values for to t al residues. Since it is the Agency's intent to us e the best data available, ISKBC suggests tha t hal f-live valu es from these two fo li ar dissipation studies (MRID 46991302 and 46991303) b e used for the fol iar dissipation half life in estimating exposure and ecological risk in the T-REX model as was done in the Probl em Formulation.
EFED R esponse: EFED acknowledges the receipt of the above mentioned studies and that relevant f oliar dissipation half lives show a 90th percentile upper confidence bound value of 7.33 day s for peanuts and potatoes. While the submitte d foliar dissipation half lives do indicate that for potatoes and peanuts, fluazinam does dissipate faster than the default value of 35 day s within T-REX, EFED included in its preliminary ri sk assessment an analysis of the results of the overall risk conclusions if the 7.33 day half life was used instead of the default 35 -days. This analysis is provided below. There is uncertainty in the RQs generated by T-REX for all registered uses of jluazinam relating to thefoliar dissipation half life. T-REX uses a default foliar dissipatio n half life of 35 days in the absence of 3 or more values that are derived from studies demonstrating that the foliar dissipation half life is less than 35 days. For jluazinam, there are two foliar dissipation studies available (peanut and potato , MRID 46991302, and 46991303, respecti vely) that estimated afoliar dissipation half life of7.33 days

. Using the cucurbit use as an example, T-REXwas run with the study derivedfoliar dissipation half life of7 .33 days instead o f the default 35 days. The results indicate that acute and chronic RQs are roughly one half for dose and dietary -ba sed RQs to birds and mammals. 

### If approximately the same results ar e shown to be truefor all uses of jluazinam, while acute and chronic RQs would be reduced

. it would not entirely eliminate acute risk to birds or chronic risk to birds and mammal s. Under the 35 day assumption of foliar dissipation half life in T-REXthere were three reg istered uses ofjluazinam (apples, cucurbits, and fruiting vegetables) that exceeded all acut e LOCs for birds and all registered uses exceeding at least the acute endangered species LOC. Using a 7.3 3 day dissipation half life would result in no uses exceeding the acute h i gh risk LOC but 12 of 14 (86%) registered uses would still exceed the acute endangered species LOC for at least one food item for birds

. For chronic risk to birds, using a l ower half lif

e would result in 9 of14 uses (64%) that exceed the chronic LOC for at least one food item compared to 13 of14 (93%) of uses that exceed the chronic LOC with default half life.
For mammals, there was no acute LOC exceedances using the default half life and so these RQs wo uld befurther reciuced. For chronic risk, eve ry registered use of jluazinam exceeded the chron ic LOC for mammals for all sizes classes and at least onefood item. With the use of the lower 7.33 day half life , this risk finding would still remain true. While there is uncertainty in th e fact that these RQs may be lower as a result of shorter half lives

2demonst r ated by available data, even the employment of this data w ould not change the overall nsk picture from how it currently stands in terms of determinations

. It is sta ted by ISKBC that "given the short dissipation half life of 7.33 days, this demonst r ates the rapid dissipation ofFluazinam, and thus acute risk should not be of concern. " As shown above, while the two submitted foliar dissipatio n indicate a shorter half life of fluazinarn than is assumed by the default value in T-REX , for birds, there would still be acute risk for listed species in 86% of registered uses and chronic risk in 64% of registered uses. For mammals, there was no acute risk indicated using the default half li fe value and even when the 7.33 value is used, chronic risk i s indi cated in all registered uses of fluazinam . Therefore, as stated previously, the overall risk picture of acute and chronic risk indicated to birds and chronic risk indicated to mammals would not be impacted. Finally, it is noted that ISKBC presented in it s comments the results ofT-REX model runs for potatoes and peanuts using both the upper bound and mean Kenaga values. As part of its standard practice for scree ning leve l risk assessment , EFED uses the results of the upper bound Kenaga values to estimate terrestrial RQs.



### 2. ISKBC Comment: EFED used the ECOSAR (v l. O) model within EPISUITE (v.4.0) in which acute and chronic toxicity was predicted for fluazinam' s eight degradation products of CAPA, DAPA , AMPA, DCPA , MAPA, HYP A, G-504 , and SDS-67200 to freshwater fish , freshwater inv ertebrates, freshwater algae, and saltwater fish. ISKBC has provided a number of studies invo lving direct measurement of metabolite /degradate toxicity to various non target organisms; these were provided in the Supplemental Reduced Risk Rationale Fluazi narn Turf Uses (IB-20 1 0

- RRR-001). In all comparable cases, the actual toxicity i s much lower (by up to several orders of magnitude) than that predicted by ECOSAR. Any refmed ecological risk assessment should take the reduced toxicity of metabolite versus parent into account. ISKB C conducted a Tier 2 modeling of fluazinam and it should be pointed out that "fluazinarn was not predicted to :adversely affect freshwater invertebrates, marine fish or estuarine/marine benthic organisms in an acute expos ure. Further, it was not predicted to adversely affect any aquatic organisms from chron ic exposure and that fluazinam risk quotients are well below the trigger value for non-endangered acute risk. " (Supplemental Reduced Risk Rationale Fluazinam Turf Uses**Respo n~;e**  to EPA Letter of October 27,2011 (MRID 48650301) Discussing Is sues Raised in the March 1 , 2011 Meeting (IB -2010-RRR- 001)).


### EFED R esponse: As part of its EC OSAR analysis in the preliminary risk assessment, EFED determined , based on the predicted toxic ity of the degradates as compared to parent fluazina rn, which degradates would be excluded from the total toxic residue (TTR) approach

. In this analysis, EFED determined that the degradates CAP A, HYPA, and DCPA would n ot be included in the TTR approach. Of the remaining 5 degradates no supplemental informat io n beyond the ECOSAR estimates was provided for DAPA and MAPA. For SDS67200 , t he sediment tox icity studies to Chironomus tentans and Hyalella azteca (MRIDs 485714 1 3 and 48571414) were cited, but these studies were already incorporated into the prelimi nary risk assessment. The remaining 2 degradates , AMPA and G-504 have estimates provided that indicate less toxicity than ECOSAR estimates. It is not indicated in response



### 3document from ISKBC whether the "NO EC, " is derived from an acute or chronic study. These stu dies are currently in review where it will be determined if there is suf ficient evidenc e that the measured toxicity of these degrada tes is less than that o f the estimates provide d by ECOSAR. 

### 3. ISKBC Comment: Several studies that were submitted by ISKBC in response to Agency requests for data were not included in the study list in Appendix F of the Preliminary Risk Assessment (PRA). These include two soil dissipation studies for Nova Scotia (MRID 45584207) a nd Ontario (MRID 45584208) , a second vascular aquatic plant study (Le mna, MRID 48571402), several diatom studies (MRID 48571403 to 06), a freshwater microcosm study (MRID 4857 l l411), and numerous studies conducted using metabolites I degradation products of fluazinam , so me of which are discussed in the text, but not listed in the reference t able. The registrant re c· eived the DERs for the two soil dissipation studies and a separate response was submitted f or these s tudies to address questions raised in those DERs. In addition, several analytical me thod studies for soil, water, and sediment were submitted to the Agency that have apparently b e :en revi ewed based on comment s in Appendix F. Since they had not seen these reviews the y requested these DERs and will respond to any comments in separa te corresponden ce. All of the above mentioned s tudies should be considered in the further environmenta l review of fluazinam.


### EFED Responses : Regarding the terrestrial field dissipation studies (MRID 45584207 and 455842 0 8), the submitted responses (MRID 49203501) were evaluated and the studies were upgraded from unacceptable to supplemental. The DE R amendments will be issued separately; however, these submissions do not alter the overall conclusions of the PRA. Regardi n g the analytical method studies for soil, water, and sediment, these DERs were previous ly issued to PRD and sen t to the ISKBC. EFED looks forward to any comment s that could address issues found in such DERs.
EFED c onfirms receipt and of the aquatic vascular plant study (MRID 48571402) as well as the aquatic nonvascular plant studies (MRIDs 48571403 , 48571404 , 48571405, and 485714 06). The aquatic vascular plant study with Lemna was not incorporated into t he prelimi n ary risk assessment because it was determined to be invalid based on solvent interference. Similarly , an aquatic nonvascular plant toxicity study with a freshwater diatom (MRID 4- 8571406) was reviewed and determined to be invalid for solvent interference. The other ref erenced aquatic nonvascular plant studies (MRIDs 48571403 , 48571404 , and 485714 0 5) were upgraded from invalid classifica tion to acceptable, supplemental, and supplemental, respectively in a 2012 memo (D394293, D394295, 394251 , 394253, 394235 , and D3 94254). Despite these studies being inadvertently not included in the preliminary risk asse ssment, these studies yielded endpoints that were higher than the most sensitive aquatic nonvascular plant toxicity study available (MRID 48612301), and therefore the risk conclus ions for aquatic nonvascular plant s would not be impacted. 

### 4. ISKBC Comment : ISKBC recently submitted a study related to the evalua tion of fluazinam uses and their relations hip t o federally listed species entitled "Endangered Species and Their Proximity to Fluaz inam Use Sites in the United States" , MRID #48879701. This study was conducted through use of the FIFRA E ndangered Species Task Force (FEST F ) Information

4Management System (IMS) and contains best available data on the proximity of federally listed species to p otential fluazinam use sites and other best available information, such as species attribute data .. ISKBC understands that the EFED document is a preliminary risk assessment and is not intended to make findings related to endangered species jeopardy. However, as the Preliminary Risk Assessment is intended to reflect the best information available to the Agency for purposes of conducting a thorough risk assessment, ISKBC feels that the information in the submitted rep ort will ultimately be very helpful to the Agency in fulfilli ng its requirement to assess risk to endangered species. ISKBC is encouraged that the risk assessment document mentions th e need for an analysis of the type in the submitted report and spec ifically mentions th

e FIFRA EJO.dangered Species Task Force (p. 60). S hould EPA's use of the data be facilitated by delivery o f the data in an alternate format , this can be readily compiled from the currently s ubmitted da ta.
EFED Res ponse: EFED acknowledges receipt of t he above referenced document.

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